platform_system_sepolicy/private/traced_probes.te
Alan Stokes 7aa40413ae Split user_profile_data_file label.
user_profile_data_file is mlstrustedobject. And it needs to be,
because we want untrusted apps to be able to write to their profile
files, but they do not have levels.

But now we want to apply levels in the parent directories that have
the same label, and we want them to work so they need to not be
MLS-exempt. To resolve that we introduce a new label,
user_profile_root_file, which is applied to those directories (but no
files). We grant mostly the same access to the new label as
directories with the existing label.

Apart from appdomain, almost every domain which accesses
user_profile_data_file, and now user_profile_root_file, is already
mlstrustedsubject and so can't be affected by this change. The
exception is postinstall_dexopt which we now make mlstrustedobject.

Bug: 141677108
Bug: 175311045
Test: Manual: flash with wipe
Test: Manual: flash on top of older version
Test: Manual: install & uninstall apps
Test: Manual: create & remove user
Test: Presubmits.
Change-Id: I4e0def3d513b129d6c292f7edb076db341b4a2b3
2020-12-11 17:35:06 +00:00

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# Perfetto tracing probes, has tracefs access.
type traced_probes_exec, system_file_type, exec_type, file_type;
type traced_probes_tmpfs, file_type;
# Allow init to exec the daemon.
init_daemon_domain(traced_probes)
tmpfs_domain(traced_probes)
# Write trace data to the Perfetto traced damon. This requires connecting to its
# producer socket and obtaining a (per-process) tmpfs fd.
perfetto_producer(traced_probes)
# Allow traced_probes to access tracefs.
allow traced_probes debugfs_tracing:dir r_dir_perms;
allow traced_probes debugfs_tracing:file rw_file_perms;
allow traced_probes debugfs_trace_marker:file getattr;
allow traced_probes debugfs_tracing_printk_formats:file r_file_perms;
# TODO(primiano): temporarily I/O tracing categories are still
# userdebug only until we nail down the denylist/allowlist.
userdebug_or_eng(`
allow traced_probes debugfs_tracing_debug:dir r_dir_perms;
allow traced_probes debugfs_tracing_debug:file rw_file_perms;
')
# Allow traced_probes to start with a higher scheduling class and then downgrade
# itself.
allow traced_probes self:global_capability_class_set { sys_nice };
# Allow procfs access
r_dir_file(traced_probes, domain)
# Allow to temporarily lift the kptr_restrict setting and build a symbolization
# map reading /proc/kallsyms.
userdebug_or_eng(`set_prop(traced_probes, lower_kptr_restrict_prop)')
allow traced_probes proc_kallsyms:file r_file_perms;
# Allow to read packages.list file.
allow traced_probes packages_list_file:file r_file_perms;
# Allow to log to kernel dmesg when starting / stopping ftrace.
allow traced_probes kmsg_device:chr_file write;
# Allow traced_probes to list the system partition.
allow traced_probes system_file:dir { open read };
# Allow traced_probes to list some of the data partition.
allow traced_probes self:global_capability_class_set dac_read_search;
allow traced_probes apk_data_file:dir { getattr open read search };
allow traced_probes dalvikcache_data_file:dir { getattr open read search };
userdebug_or_eng(`
# search and getattr are granted via domain and coredomain, respectively.
allow traced_probes system_data_file:dir { open read };
')
allow traced_probes system_app_data_file:dir { getattr open read search };
allow traced_probes backup_data_file:dir { getattr open read search };
allow traced_probes bootstat_data_file:dir { getattr open read search };
allow traced_probes update_engine_data_file:dir { getattr open read search };
allow traced_probes update_engine_log_data_file:dir { getattr open read search };
allow traced_probes { user_profile_root_file user_profile_data_file}:dir { getattr open read search };
# Allow traced_probes to run atrace. atrace pokes at system services to enable
# their userspace TRACE macros.
domain_auto_trans(traced_probes, atrace_exec, atrace);
# Allow traced_probes to kill atrace on timeout.
allow traced_probes atrace:process sigkill;
# Allow traced_probes to access /proc files for system stats.
# Note: trace data is NOT exposed to anything other than shell and privileged
# system apps that have access to the traced consumer socket.
allow traced_probes {
proc_meminfo
proc_vmstat
proc_stat
}:file r_file_perms;
# Allow access to the IHealth and IPowerStats HAL service for tracing battery counters.
hal_client_domain(traced_probes, hal_health)
hal_client_domain(traced_probes, hal_power_stats)
# Allow access to Atrace HAL for enabling vendor/device specific tracing categories.
hal_client_domain(traced_probes, hal_atrace)
# On debug builds allow to ingest system logs into the trace.
userdebug_or_eng(`read_logd(traced_probes)')
###
### Neverallow rules
###
### traced_probes should NEVER do any of this
# Disallow mapping executable memory (execstack and exec are already disallowed
# globally in domain.te).
neverallow traced_probes self:process execmem;
# Block device access.
neverallow traced_probes dev_type:blk_file { read write };
# ptrace any other app
neverallow traced_probes domain:process ptrace;
# Disallows access to /data files.
neverallow traced_probes {
data_file_type
-apk_data_file
-dalvikcache_data_file
-system_data_file
-system_data_root_file
-system_app_data_file
-backup_data_file
-bootstat_data_file
-update_engine_data_file
-update_engine_log_data_file
-user_profile_root_file
-user_profile_data_file
# TODO(b/72998741) Remove vendor_data_file exemption. Further restricted in a
# subsequent neverallow. Currently only getattr and search are allowed.
-vendor_data_file
-zoneinfo_data_file
with_native_coverage(`-method_trace_data_file')
}:dir *;
neverallow traced_probes system_data_file:dir ~{ getattr userdebug_or_eng(`open read') search };
neverallow traced_probes zoneinfo_data_file:dir ~r_dir_perms;
neverallow traced_probes { data_file_type -zoneinfo_data_file }:lnk_file *;
neverallow traced_probes {
data_file_type
-zoneinfo_data_file
-packages_list_file
with_native_coverage(`-method_trace_data_file')
}:file *;
# Only init is allowed to enter the traced_probes domain via exec()
neverallow { domain -init } traced_probes:process transition;
neverallow * traced_probes:process dyntransition;